Fiberglass-reinforced built-up roofing systems have been holding their own in the market.
If a storm forces the crew to “dry in” the roof, the acceptable solution is to use a minimum of two plies of fiberglass felt with a very light squeegee coat of asphalt to make the roof water tight. The job is then completed by cleaning debris and moisture from the roof and finishing with four plies laid up 8 1/2 inches apart as designed.